(CNN) -- Portuguese club Benfica have sent promising young United States international Freddy Adu on loan to French club Monaco for the 2008-09 season.

Freddy Adu will seek to establish himself at Monaco after a difficult time with Benfica.

The 19-year-old attacking midfielder struggled to earn a regular place in his first season with Benfica, and has been told that he is not part of new coach Quique Flores' plans for the upcoming campaign.

Monaco, who finished 12th in the French league, will have the option to buy the Ghana-born player at the end of his loan.

Adu, who has scored five times in 21 appearances for Benfica despite starting only two matches, may miss the start of the principality club's season as he will be part of the U.S. squad for next month's Olympic Games in China.

Benfica, who confirmed Adu's move on their Web site, have recently signed Argentine playmaker Pablo Aimar from relegated Spanish club Real Zaragoza.

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Flores is the club's fourth coach in the past year, and takes over the ailing 31-time Portuguese champions after a season in which they finished fifth and failed to qualify for the Champions League.

Adu moved to the U.S. with his family at the age of eight and at 14 became the youngest player ever to sign a professional Major League Soccer contract.

He started his MLS career with Washington-based D.C. United in 2004, being twice selected in the All-Star lineup, and was traded to Real Salt Lake in December 2006 before leaving six months later to join Benfica.

Adu made his senior U.S. debut in November 2007, and helped the Under-23 team qualify for Beijing with two goals in the qualifying semifinal victory against Canada which put his country through along with Honduras.